A hybrid vehicle may include an internal combustion engine and an electric motor to propel the vehicle. The motor may propel the vehicle at lower driver demand torque levels, and the engine may operate to provide higher driver demand torques. The engine may also be activated at lower ambient temperatures to heat the vehicle's passenger cabin. Coolant from the engine may be routed to a heater core located within the passenger cabin to heat the passenger cabin. The engine may be activated in response to a request to heat the passenger cabin even though driver demand torque may be low. However, starting the engine to supply heat to the passenger cabin may reduce vehicle fuel economy. Therefore, it would be desirable to provide a way of heating the passenger cabin that has less effect on vehicle fuel economy.
The inventors herein have recognized the above-mentioned issues and have developed an engine operating method, comprising: deactivating one or more cylinders of an engine via a controller in response to a request to heat a passenger cabin.
By deactivating one or more engine cylinders in response to a request to heat a passenger cabin, it may be possible to provide the technical result of reducing fuel consumption by an engine while increasing passenger cabin heating. In particular, a first group of engine cylinders may remain active while a second group of engine cylinders are deactivated. The active engine cylinders may operate at a higher engine load such that the active engine cylinders exhibit reduced pumping losses and higher efficiency. Further, engine coolant may be supplied to only the first group of cylinders so that less engine coolant is warmed, thereby reducing the mass of coolant being warmed and speeding up heat transfer from the engine to the passenger cabin.
The present description may provide several advantages. For example, the approach may improve vehicle fuel economy during cold ambient conditions. Additionally, the approach may improve passenger cabin heating by reducing the thermal mass in the passenger cabin heating system. Further, the approach may be applied to gasoline, diesel, and alternative fuel engines of hybrid vehicles.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.